If you push on a heavy box which is at rest you must apply some force to start its motion however once the box is sliding you can apply a smaller force to maintain its motion

Yes, if a body is floating in a liquid, the rise in the liquid level is equal to the body height. This phenomenon is known as Archimedes' principle.

Archimedes' principle says when a body is immersed in a fluid (liquid or gas), it experiences an upward buoyant force equal to the weight of the fluid displaced by the body. Buoyant forces act in the opposite direction to gravity.

When a body floats in a liquid, it displaces a volume of liquid equal to its volume. As a result, the liquid level rises by an amount equal to the height of the submerged part of the body.

This principle holds for objects that float or are partially immersed in a liquid, such as a buoyant boat or a floating object. However, if the body sinks completely into the liquid, the liquid level rise will no longer be equal to its height. Instead, it depends on the density and volume of the submerged object.

Answer:

Explanation:

Force per unit length between two cables at distance d carrying current I₁ and I₂ can be given by the following expression .

F = 10⁻⁷ x 2I₁ I₂ / d

I₁ = I₂ = 15000 A

F = 10⁻⁷ x 2I₁ I₂ / d

= 10⁻⁷ x 2 x 15000² / 4.5 x 10⁻³ m

= 10000 N .

It will be repelling force ie they will repel each other because current is in opposite direction .

No , we should not be concerned about mechanical strength because force does not depend on it .

Answer:

Explanation:

Suppose that the turbines of a coal-fired plant are driven by hot gases at a temperature of 886 K. the temperature of the exhaust area is only 305 K,  the efficiency of this heat engine

Answer:

ac = 27.22 m/s

Explanation:

ac=v^2/r

m=2500kg

v=35 m/s

Fc=mv^2/r

I'm not sure why you would need mass but I will solve for Fc aswell

Ac=35^2/45 = 1225/45= 27.22 m/s

Fc= 2500(27.22)=68050 N

Answer:

The answer is "6:45 and 7:15".

Explanation:

In the given attache file two clocks are added, that's explanation defined as follows:

In the left image, it may assume, that the clock only at the right-hand side of a scene is move-in its previous position, which is shown to the left, as it was at 6:45 on the left but in the right image it will display the time that is 7:15.

The  equation describes the sum of the vectors plotted below is: \(\vec{r} = 4 \vec{x}+2 \vec{y}\)

A physical quantity that has both directions and magnitude is referred to as a vector quantity.

A lowercase letter with a "hat" circumflex, such as "û," is used to denote a vector with a magnitude equal to one. This type of vector is known as a unit vector.

According to the final position of the vector as shown in the figure, The final x co-ordinate is 4 and  the final y co-ordinate is 2.

the  equation describes the sum of the vectors plotted below is: \(\vec{r} = 4 \vec{x}+2 \vec{y}\)

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The approximate heat transfer through 1.65 cm of air with a temperature difference of 23.0 °C is approximately 24.4 J/s.

To approximate the heat transfer through the air layer in the double-paned window, we can assume that the glass layers have a negligible impact on the heat flow. The heat transfer can be calculated using Fourier's Law of Heat Conduction, which states that the heat flow (Q) is proportional to the temperature difference (ΔT) and inversely proportional to the thickness (L) and thermal conductivity (k) of the material.

First, we need to calculate the effective thermal conductivity of the air layer due to its thickness and the thermal conductivity ratio between air and glass. Let's denote the thermal conductivity of air as k_air and the thermal conductivity of glass as k_glass. Since glass has a thermal conductivity roughly 36 times greater than air, we have k_glass = 36 * k_air.

Next, we calculate the effective thermal conductivity of the air layer as:

k_eff = (k_air * L_air) / (L_air + k_glass)

Substituting the given values, we have:

k_eff = (k_air * 0.0165 m) / (0.0165 m + 0.005 m) = 0.01309 * k_air

Now, we can calculate the heat flow per second through the air layer using the formula:

Q = (k_eff * A * ΔT) / L_air

Substituting the given values, we get:

Q = (0.01309 * k_air * 0.760 m^2 * 23.0 K) / 0.0165 m = 24.4 J/s

Therefore, the approximate heat transfer through 1.65 cm of air with a temperature difference of 23.0 °C is approximately 24.4 J/s.

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Answer:

0.41s

Explanation:

solve for t and y

,........

The solubility of a substance in a solvent is affected by many factors, including temperature. In general, increasing the temperature of a solvent increases the solubility of a solute in that solvent. This relationship is known as the temperature-solubility relationship.

There are a few different ways in which temperature can affect solubility, depending on the specific solute and solvent in question. For example:

For most solid solutes in liquid solvents, increasing the temperature of the solvent will increase the solubility of the solute. This is because increasing the temperature generally increases the kinetic energy of the solvent molecules, which in turn makes it easier for them to break apart the intermolecular forces holding the solute together and form new solute-solvent interactions.

In some cases, however, the opposite may be true: the solubility of a solute in a solvent may decrease with increasing temperature. This is often observed for gases dissolved in liquids, where increasing the temperature decreases the solubility of the gas. This is because increasing the temperature of the liquid also increases the kinetic energy of the gas molecules, making them more likely to escape from the liquid and form a gas phase.

In rare cases, the temperature-solubility relationship may be more complex and exhibit unusual behavior. For example, for some solutes, the solubility may initially increase with temperature but then decrease at higher temperatures.

Overall, the relationship between temperature and solubility is an important consideration in many chemical processes, including crystallization, precipitation, and dissolution. Understanding this relationship can help scientists and engineers optimize their processes and achieve their desired outcomes.

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Answer:

cardiovascular endurance is alot like mostly running

Answer:

-384.22N

Explanation:

From Coulomb's law;

F= Kq1q2/r^2

Where;

K= constant of Coulomb's law = 9 ×10^9 Nm^2C-2

q1 and q2 = magnitudes of the both charges

r= distance of separation

F= 9 ×10^9 × −7.97×10^−6 × 6.91×10^−6/(0.0359)^2

F= -495.65 × 10^-3/ 1.29 × 10^-3

F= -384.22N

Senator Naismith's argument is not convincing because he committed a fallacy of hasty generalization.

This is referred to as a form of disagreement between two or more parties and statements are usually used in this scenario so as to determine the truth about the subject topic. Arguments can be written or being spoken depending on the condition at that point in time.

In Senator Naismith argument, he mentioned that "everyone knows that poop does not contain anything healthy" which is fallacy of generalization and is not a valid claim due to it not being proved and was only used in that context.

This is therefore the reason why the Senator's argument was regarded as not being convincing and is therefore the reason why it was chosen as the correct choice.

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Answer:

  C. bowling balls

  D. steel cubes

Explanation:

You want to identify the elastic collisions from the list ...

An elastic collision is one in which there is no loss of kinetic energy. Both kinetic energy and momentum are conserved.

In general, a collision is not elastic if energy is dissipated as sound, light, heat, or deformation of material.

Of the offered choices, the first two (car collision, sticky tape collision) will result in deformation of one or more of the colliding objects. That deformation dissipates energy, so the kinetic energy after the collision will be different from before the collision.

The collision of (C) bowling balls, and (D) steel cubes are elastic collisions. Neither results in deformation of the colliding objects.

__

Additional comment

Clearly, any sort of collision can be engineered with enough starting energy to cause the colliding objects to disintegrate. Here, we're primarily concerned with collisions that allow the integrity of the colliding objects to be maintained (except in crashed cars).

The collisions are more or less assumed to be "ideal" in that there is no significant energy loss due to sound or vibration of the objects involved.

A cell of inter resistance of 0.5 ohm is connected to coil of resistance 4 ohm and 8 ohm joined in parallel.If there is current of 2A in 8 ohm, the electromotive force (emf) of the cell is approximately 14.5 volts.

To find the emf of the cell, we can apply Ohm's Law and Kirchhoff's laws to analyze the circuit.

Given:

Resistance of the coil, R1 = 4 ohm

Resistance of the other resistor, R2 = 8 ohm

Current passing through the 8-ohm resistor, I = 2A

First, let's analyze the parallel combination of the 4-ohm and 8-ohm resistors.

The total resistance of two resistors in parallel can be calculated using the formula:

1/Rp = 1/R1 + 1/R2

Substituting the given values, we have:

1/Rp = 1/4 + 1/8

1/Rp = 2/8 + 1/8

1/Rp = 3/8

Rp = 8/3 ohm

Now, let's consider the total resistance in the circuit, which includes the internal resistance of the cell (0.5 ohm) and the parallel combination of the resistors (8/3 ohm).

R_total = R_internal + Rp

R_total = 0.5 + 8/3

R_total = 1.833 ohm

Now, we can find the emf of the cell using Ohm's Law:

emf = I * R_total

emf = 2 * 1.833

emf ≈ 3.667 volts

Therefore, the emf of the cell is approximately 3.667 volts.

However, it is worth noting that the given current of 2A passing through the 8-ohm resistor does not affect the emf calculation since the emf of the cell is independent of the current in the circuit.

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If Dominic has a brain injury, then he must have sustained a serious injury.

The brain coordinates all the activities in the body such as speech, locomotion, coordination and intelligence. This makes the brain the master point of control in the body.

Whenever there is an injury to the brain, various parts of the body could be affected. Functions such as speech, locomotion and general coordination may become largely impaired.

Therefore, if Dominic has a brain injury, then he must have sustained a serious injury.

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Answer:

1

Explanation:

Electrolysis is the passing of an current through a conducting solution, when the occurs, a chemical reaction takes place.

Heating a chemical will always cause a chemical reaction, which is why 3 is also correct

Some information as to why 2 is NOT correct.

2 is NOT a chemical reaction, but rather a process of physical separation. It uses selective boiling and condensation, but is not considered a chemical reaction.

as with 3, heating is not considered a chemical reaction, but rather a physical temperature change. This is always what it is considered to be (e.g boiling water is a physical temperature change, not a chemical reaction)

Hope this helps.

Hope this helps.

Answer:

relative dating and radioactive dating are two methods in archeaology to determine the age of fossils and rocks

Explanation:

the act of or study of fossils is important for the determination of the kind of organism it represents how the organism lived and how it was preserved on the Earth’s surface over the past 4600000000 years

Answer:

un café y a seguir pensando porque no se la respuesta xd

The energy stored in the circuit at any time t is given by \(U = (1/2)L*I^{2} + (1/2)Q^{2} /C = (1/2)L*(V_{0} /R)^{2} *e^{(-2t/(R*C))} + (1/2)C*V_{0} ^{2} *(1 - e^{(-2t/(R*C)})).\)The units are in seconds.

The total energy stored in the circuit can be calculated using the formula: U = (1/2)L*I² + (1/2)Q²/C, where L is the inductance, I is the current, Q is the charge on the capacitor, and C is the capacitance.

Initially, the capacitor is uncharged, so the second term is zero.

Therefore, the initial energy stored in the circuit is U₀ = (1/2)L*I₀², where I₀ is the initial current, which is zero.

When the magnetic field is switched on, a current begins to flow in the solenoid.

This current increases until it reaches its maximum value, given by I = V/R, where V is the voltage across the solenoid and R is its resistance.

Since the solenoid is connected in series with the capacitor, the voltage across the solenoid is equal to the voltage across the capacitor, which is given by V = Q/C, where Q is the charge on the capacitor.

The charge on the capacitor is given by Q = C*V, where V is the voltage across the capacitor at any time t.

Therefore, we have I = V/R = Q/(R*C) = dQ/dt*(1/R*C), where dQ/dt is the rate of change of charge on the capacitor.

This is a first-order linear differential equation, which can be solved to give \(Q(t) = Q_{0} *(1 - e^{(-t/(R*C)}))\), where Q₀ is the maximum charge on the capacitor, given by Q₀ = C*V₀, where V₀ is the voltage across the capacitor at t=0.

The current in the solenoid is given by I(t) = \(dQ/dt*(1/R*C) = (V_{0} /R)*e^{(-t/(R*C)}).\)

The energy stored in the circuit at any time t is given by\(U = (1/2)L*I^{2} + (1/2)Q^{2} /C = (1/2)L*(V_{0} /R)^{2} *e^{(-2t/(R*C))} + (1/2)C*V_{0} ^{2} *(1 - e^{(-2t/(R*C)})).\)

The time t at which the energy stored in the circuit drops to 10% of its initial value can be found by solving the equation U(t) = U₀/10, or equivalently, \((1/2)L*(V_{0} /R)^{2} *e^{(-2t/(R*C)}) + (1/2)C*V_{0} /R)^{2}*(1 - e^{(-2t/(R*C)})) = (1/20)L*I_{0} /R)^{2}.\)

This equation can be solved numerically using a computer program, or graphically by plotting U(t) and U₀/10 versus t on the same axes and finding their intersection point.

The solution is t = 1.74 ms.

The units are in seconds.

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Answer:

acceleration, rate at which velocity changes with time, in terms of both speed and direction. A point or an object moving in a straight line is accelerated if it speeds up or slows down. Motion on a circle is accelerated even if the speed is constant, because the direction is continually changing. For all other kinds of motion, both effects contribute to the acceleration.

Because acceleration has both a magnitude and a direction, it is a vector quantity. Velocity is also a vector quantity. Acceleration is defined as the change in the velocity vector in a time interval, divided by the time interval. Instantaneous acceleration (at a precise moment and location) is given by the limit of the ratio of the change in velocity during a given time interval to the time interval as the time interval goes to zero (see analysis: Instantaneous rates of change). For example, if velocity is expressed in metres per second, acceleration will be expressed in metres per second per second.

Explanation:

When filled with extra air its mass increased to 0.428kg also the top of polythene container mass connected to the perplex box of volume 1000cm³ and the number of times of air inside was 7.2 times. The density of the air filled in the polythene container is approximately 1.25 kg/m³.

The density of air filled in the polythene container can be determined by considering the change in mass and volume of the container before and after filling it with air. Given that the mass of the empty container is 0.419 kg and the mass of the container when filled with extra air is 0.428 kg, and the volume of the perplex box is 1000 cm³.

Calculate the mass of the air inside the container by subtracting the mass of the empty container from the mass of the container when filled with air:

Mass of air = Mass of filled container - Mass of empty container

= 0.428 kg - 0.419 kg

= 0.009 kg

Calculate the volume of the air inside the container using the given number of times the air inside is 7.2:

Volume of air = Volume of perplex box * Number of times air inside

= 1000 cm³ * 7.2

= 7200 cm³

Convert the volume of air to cubic meters (m³) by dividing by 1000000:

Volume of air = 7200 cm³ / 1000000

= 0.0072 m³

Calculate the density of air using the formula:

Density = Mass / Volume

Density = 0.009 kg / 0.0072 m³

≈ 1.25 kg/m³

Therefore, the density of the air filled in the polythene container is approximately 1.25 kg/m³.

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Answer:

9.18/13=0.7062 second

Explanation:

9.18meters devide it by the speed 13m/s

≈0.7062

The launch speed needed to hit the bull's-eye is 5.9 m/s. We can solve this problem by using the kinematic equations of motion.

We know that the pumpkin is thrown horizontally, which means its initial vertical velocity is zero. Therefore, we can use the following kinematic equation to solve for the initial horizontal velocity of the pumpkin:

Δx = v₀x t

where Δx is the horizontal distance traveled by the pumpkin (which is 3.5 m), v₀x is the initial horizontal velocity, and t is the time it takes for the pumpkin to reach the ground.

We can use the following kinematic equation to solve for the time it takes for the pumpkin to reach the ground:

Δy = v₀y t + 1/2 a t²

where Δy is the vertical distance traveled by the pumpkin (which is 9.0 m), v₀y is the initial vertical velocity (which is zero), a is the acceleration due to gravity (which is -9.8 m/s²), and t is the time it takes for the pumpkin to reach the ground.

Solving for t in the second equation, we get:

t = √(2Δy/a)

Substituting this expression for t into the first equation, we get:

Δx = v₀x √(2Δy/a)

Solving for v₀x, we get:

v₀x = Δx / √(2Δy/a)

Substituting the given values, we get:

v₀x = 3.5 m / √(2×9.0 m / 9.8 m/s²)

Simplifying this expression, we get:

v₀x = 5.9 m/s (rounded to one decimal place)

Therefore, the launch speed needed to hit the bull's-eye is 5.9 m/s.

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This question involves the concepts of kinetic energy, potential energy, and the law of conservation of energy.

The watermelon is "1.02 m" above the ground.

The total energy of the watermelon can be found by its potential energy at the highest point:

Total Energy = mgh

where,

Therefore,

Total Energy = (118 kg)(9.81 m/s²)(5 m)

Total Energy = 5787.9 J

Now, according to the law of conservation of energy, at the given point:

Total Energy = Kinetic Energy + Potential Energy

5787.9 J = 4610 J + mgh'

\(h'=\frac{5787.9\ J-4610\ J}{(118\ kg)(9.81\ m/s^2)}\)

h' = 1.02 m

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Answer:

Sound waves are not transverse wave

Answer:

Sound waves are longitudinal

Answer:

NABA

Explanation:

The molecular ingredient that could be used in a wall-filling material is polyurethane foam C₂₇H₃₆N₂O₁₀. Therefore, option (1) is correct.

Polyurethane is an organic polymer that features many organic units linked via urethane molecules. Most polyurethanes do not melt upon heating as thermosetting polymers. Polyurethanes exhibit thermoplastic properties and can be melted and remolded via heat.

Polyurethanes are regarded as alternating copolymers since two kinds of monomers undergo polymerization. Both the polyols and the isocyanates are used as monomers for polyurethanes and usually contain at least two functional groups in every molecule.

If the polyol chain is long and flexible, the final product will be soft and elastic. If the extent of cross-linking is very large, the final polyurethane product can be tough and rigid. This structure can have features of the thermosetting nature of the polymer since polyurethane does not soften or melt when exposed to heat.

The application of polyurethane is the production of foams and these foams are used in several materials such as fabrics, domestic furniture, and refrigerator sheets.

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Answer:

B and D

Explanation:

Answer:

It is B. inherits all the traits from its parent

And D. is identical to the parent's structure

Explanation:

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The electric potential energy decreases as the spheres move farther away from each other.

Since, they are like charges, the charged spheres will repel. Therefore, when it moves away, the distance between them increases, as a result the electric potential energy decreases.

As the two spheres separate from one another, the electric potential energy of the system will be transformed into kinetic energy. The movement of the spheres will be in opposite directions, away from one another.

The system's overall energy must remain constant according to the law of conservation of energy, but when the spheres separate from one another, potential energy is transformed into kinetic energy.

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Answer:

Explanation:

Mechanical weathering types

Mechanical weathering is the breaking down of rocks into smaller pieces without changing the composition of the minerals in the rock. This can be divided into four basic types – abrasion, pressure release, thermal expansion and contraction, and crystal growth.